The present invention relates to an optical lens, in particular for use as a spectacle lens, having a lens element and a coating for producing an antistatic effect, said coating being applied to the lens element and having a plurality of layers.
Furthermore, the present invention relates to a method for producing an antistatic coating having a plurality of layers for a lens element.
Antistatic spectacle lenses afford the advantage that dirt particles adhere to the spectacle lenses to a lesser extent on account of absent electrostatic attraction forces. Without an antistatic coating, a spectacle lens is soiled more rapidly and therefore has to be cleaned more often. Furthermore, the dirt is often difficult to remove. Therefore, in the case of the coating of spectacle lenses, a conductive and thus antistatic layer is usually inserted into the coating. For this purpose, hitherto an individual layer has been inserted into the antireflective coating of the spectacle lens.
One example of a coating can be gathered from the document US 2003/0179343 A1, for example. It describes a coating in which an antistatic layer composed of indium tin oxide (ITO) having a specific thickness is inserted into the antireflective coating. However, the insertion of such an ITO layer into the antireflective coating has certain disadvantages such as higher costs for the coating and impairment of the mechanical and optical properties of the antireflective coating.
Therefore, it is an object of the present invention to provide an antistatic coating for an optical lens, more particularly a spectacle lens, which can be integrated simply and cost-effectively into an antireflective coating of the optical lens.